Development of fluorescent lateral flow test strips based on an electrospun molecularly imprinted membrane for detection of triazophos residues in tap water†
Herein, a molecularly imprinted membrane chromatography strip using a combination of electrospinning, molecular imprinting, and fluorescent lateral flow test strips (LFTS) was developed for specific recognition of triazophos residues in tap water. A molecularly imprinted T-line (detection) was prepared on a nitrocellulose (NC) membrane by an electrospinning technique, and goat anti-mouse IgG antibody (C-line) was used as a quality control line for the strip. Subsequently, a triazophos hapten-murine IgG/fluorescein isothiocyanate conjugate (THBu–IgG–FITC) was synthesized. The rapid detection of triazophos residues was established based on fluorescence changes generated by direct competition between the THBu–IgG–FITC fluorescent probe and target triazophos on the molecularly imprinted binding sites. Parameters including the spinning solution, electrospinning conditions, surfactant, molecularly imprinted polymer (MIP) concentration, concentration of the fluorescent probe, and competition mode were optimized. The developed method showed good linearity (R2 = 0.9906) over the concentration range of 20–500 μg L−1 with a limit of detection (LOD) of 20 μg mL−1 in tap water samples. The whole detection procedure could be accomplished within 18 min. In sum, the electrospun membrane with a MIP is extremely stable to fix the recognition element of lateral flow test strips and could provide a new strategy for rapid detection of pesticide residues.